In an evolved packet system (EPS) network architecture defined by the 3rd Generation Partnership Project (3GPP), there is a scenario in which a Serving Gateway (SGW) and a Packet Data Network (PDN) gateway (PGW) are separately deployed.
In the scenario in which the SGW and the PGW are separately deployed, when a fault occurs in the PGW, it is defined in a 3GPP protocol that when sensing that a fault occurs in the PGW, the SGW sends, to an Mobility Management Entity (MME), a message for notifying the MME that a fault occurs in the PGW, so that the MME determines, after receiving the message, that a fault occurs in the PGW.
When receiving the message that is sent by the SGW and used for notifying that a fault occurs in the PGW, the MME needs to traverse context information in an information exchange system, delete a PDN connection established with the faulty PGW, and determine user equipment that need to be notified to reestablish a Packet Date Network (PDN) connection with the faulty PGW and to re-initiate a communication service request.
It is discovered by means of research that in a process in which the MME initiates PDN connection reestablishment when learning that a fault occurs in the PGW, a signaling transmission procedure of a PGW fault message is added, and moreover, an echo message negotiation on whether the procedure of the PGW fault message is supported needs to be performed between the MME and the SGW. As a result, a signaling transmission link is relatively long, resulting in low system service processing efficiency.